Rare George Washington letter up for auction

WASHINGTON (CBS) -- History buffs with deep pockets can now bid to own a unique piece of Americana. A rare George Washington letter endorsing the adoption of United States constitution will be offered by Christie's of New York. The seven page letter addressed to Pennsylvania delegate General John Armstrong was penned on April 25, 1788, by Washington from Mount Vernon during the national debate over ratification.

Patrick McGrath, books and manuscripts specialist at Christie's, says the letter is unique because Washington looks forward to a post-ratification future in which an expanding U.S. becomes a unified empire of liberty. McGrath says, "He looks to the ways in which a unified country under this new charter would attract immigrants, would promote greater cohesion and economic activity and greater stability politically. So, he's looking at the bigger picture beyond ratification."

The autographed letter is expected to bring upwards of $2 million. According to McGrath the company auctioned a similar letter addressed to Washington's nephew, Bushrod Washington, for around $3 million in 2009.

Other items in the auction include an Edgar Allen Poe unpublished letter establishing the "Tell-Tale Heart" publication information and a signed Abraham Lincoln letter.

The Washington letter is the final auction piece on June 21 and available for worldwide bidding on the Christie's website for account members.